buildkit/executor/oci/mounts.go

103 lines
2.6 KiB
Go

package oci
import (
"context"
"path/filepath"
"strings"
"github.com/containerd/containerd/containers"
"github.com/containerd/containerd/oci"
specs "github.com/opencontainers/runtime-spec/specs-go"
)
func withRemovedMount(destination string) oci.SpecOpts {
return func(_ context.Context, _ oci.Client, _ *containers.Container, s *specs.Spec) error {
newMounts := []specs.Mount{}
for _, o := range s.Mounts {
if o.Destination != destination {
newMounts = append(newMounts, o)
}
}
s.Mounts = newMounts
return nil
}
}
func withROBind(src, dest string) oci.SpecOpts {
return func(_ context.Context, _ oci.Client, _ *containers.Container, s *specs.Spec) error {
s.Mounts = append(s.Mounts, specs.Mount{
Destination: dest,
Type: "bind",
Source: src,
Options: []string{"nosuid", "noexec", "nodev", "rbind", "ro"},
})
return nil
}
}
func withCGroup() oci.SpecOpts {
return func(_ context.Context, _ oci.Client, _ *containers.Container, s *specs.Spec) error {
s.Mounts = append(s.Mounts, specs.Mount{
Destination: "/sys/fs/cgroup",
Type: "cgroup",
Source: "cgroup",
Options: []string{"ro", "nosuid", "noexec", "nodev"},
})
return nil
}
}
func hasPrefix(p, prefixDir string) bool {
prefixDir = filepath.Clean(prefixDir)
if filepath.Base(prefixDir) == string(filepath.Separator) {
return true
}
p = filepath.Clean(p)
return p == prefixDir || strings.HasPrefix(p, prefixDir+string(filepath.Separator))
}
func removeMountsWithPrefix(mounts []specs.Mount, prefixDir string) []specs.Mount {
var ret []specs.Mount
for _, m := range mounts {
if !hasPrefix(m.Destination, prefixDir) {
ret = append(ret, m)
}
}
return ret
}
func withBoundProc() oci.SpecOpts {
return func(_ context.Context, _ oci.Client, _ *containers.Container, s *specs.Spec) error {
s.Mounts = removeMountsWithPrefix(s.Mounts, "/proc")
procMount := specs.Mount{
Destination: "/proc",
Type: "bind",
Source: "/proc",
// NOTE: "rbind"+"ro" does not make /proc read-only recursively.
// So we keep maskedPath and readonlyPaths (although not mandatory for rootless mode)
Options: []string{"rbind"},
}
s.Mounts = append([]specs.Mount{procMount}, s.Mounts...)
var maskedPaths []string
for _, s := range s.Linux.MaskedPaths {
if !hasPrefix(s, "/proc") {
maskedPaths = append(maskedPaths, s)
}
}
s.Linux.MaskedPaths = maskedPaths
var readonlyPaths []string
for _, s := range s.Linux.ReadonlyPaths {
if !hasPrefix(s, "/proc") {
readonlyPaths = append(readonlyPaths, s)
}
}
s.Linux.ReadonlyPaths = readonlyPaths
return nil
}
}